Officials hope to limit spread of citrus disease found in N.O.

Provided photo by Raj Singh, LSU AG Center -- A disease called citrus canker has been found in New Orleans, marking the disease's first appearance in Louisiana. Officials this week destroyed three trees afflicted with the disease in City Park.
Provided photo by Raj Singh, LSU AG Center -- A disease called citrus canker has been found in New Orleans, marking the disease's first appearance in Louisiana. Officials this week destroyed three trees afflicted with the disease in City Park.

City Park workers this week dug up — and federal officials incinerated — three orange trees growing in the park that were afflicted with citrus canker, a pernicious bacterial disease that hasn’t been seen in Louisiana in over 100 years.

It is a “devastating disease” that can cause citrus trees to stop producing fruit, said Louisiana State University AgCenter plant scientist Raj Singh, who was on hand for the removal of the trees.

Louisiana is only the second state in the country, after Florida, to have encountered the disease in the modern era. So far, it’s only been seen in Orleans Parish. “It is a serious disease of citrus because it causes defoliation, premature fruit drop, blemished fruits and tree decline, and ultimately, the infected tree stops producing fruit,” Singh said in a statement issued by the LSU AgCenter.

Federal officials are hopeful that the citrus-canker outbreak in Louisiana is limited to the city. A team of local, state and federal officials is gearing up to survey the area around the park, hoping to determine the source of the outbreak and the extent of the problem.

“We’ve only found it in Orleans Parish, and only right there in City Park,” said Bill Spitzer, an official with the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, Plant Protection and Quarantine section.

“City Park didn’t want to spread the disease, so they decided to go ahead and remove them.”

The infected trees were quarantined by federal officials after being removed from the Big Lake area of City Park, “near the little green pump-house,” City Park spokesman John Hopper said. They were later incinerated by the USDA.

“We are, and we will continue to fully comply with the USDA because they are the people who are the experts on the subject,” Hopper added. There are several dozen citrus trees in City Park, Hopper said, but only three had the disease.

The trees, which were planted in the park around 2010, exhibited tell-tale lesions on their leaves and stems that indicated the unwelcome bacterial canker had arrived in New Orleans.

The infected trees were discovered by a federal agriculture official, Spitzer said.

Spitzer noted that he didn’t believe the City Park orange trees were the “source tree” of the infection. Rather, he said, a New Orleanian either brought an afflicted tree into the parish from Florida, or had it shipped here. He said the canker infestation in the trio of trees appeared to be less than a year old, lending to his conjecture that “the disease blew into the park, from a short distance.”

He said 2012’s Hurricane Isaac may have been the culprit that unloosed the unwelcome bacteria in the direction of the park.

“That’s why we are doing a survey around that park, to determine what is the source tree, if it’s still alive, see if other trees are affected,” Spitzer said. “If an individual thinks he’s got it in one of his trees, call the county agent of the USDA office, and we may take a look at it.”

Citrus canker disease has run roughshod over the $9 billion Florida citrus industry for about two decades. Louisiana is one of several states that bans the importation of any citrus trees from that state, Singh said.

Florida had gotten its citrus-canker problem under control by 2004, but several hurricanes that year set back the eradication efforts.

“Florida is covered with canker,” Spitzer said. “They gave up on eradication and went to management” of the disease after 2004.

Louisiana’s commercial and homegrown citrus-tree industry pales in size to the Florida’s — about 600 acres are devoted statewide to citrus trees, contributing about $5 million to the state economy annually, Singh said.

Backyard citrus trees — primarily lemons, limes, grapefruits, satsumas and oranges — are popular and abundant in New Orleans. Plaquemines Parish, meanwhile, has a substantial citrus industry.

Singh said he will train local officials around the state to identify the telltale signs of citrus canker.

The first symptoms are tiny blisters, which then develop into full-blown lesions. “As the lesion ages, the center becomes raised and corky and may fall out, giving it a shot-hole appearance,” Singh wrote.

Singh noted that the relatively small size of Louisiana’s citrus industry shouldn’t discount the disease’s potential impact.

“It is a potential threat because down the road we have Texas — and Texas has a big citrus industry,” Singh said. “The main problem is that people who really like their citrus, they move their citrus product across state lines. That can cause an infection in that state.”

Spitzer said the USDA would be bringing in Florida officials later this month to supplement the survey team he’ll be deploying in Orleans Parish and elsewhere around the state. He added that there’s no public health risk to consuming fruit from infected trees. “There’s no impact on human health or on animals at all,” Spitzer said.